This is a pretty dumb paper...meat eating is one of the very things that made us human! Our digestive tracts shortened because we started eating meat, providing room for our brains. We diverged from gorillas/chimps for a reason......

How does it make sense that a single diet is prescribed for an entire suborder of species? Gorillas are herbivores, although frugivorous at times: completely distinct from gibbons which are strictly frugivorous: these species differ only at the family level. Even old world monkeys (cercopithecoidea, members of the same super family) have different diets: Ceboids have rumen-like stomachs and eat only grasses, have slicing molars, and cercopithecines have crushing molars and eat only fruit. Prescribing a single diet to all of these animals would be a HORRIBLE idea. Not to mention, even chimps are also distinct from humans, although we only differ at the , as their diet typically consists of much less meat.

This is a pretty dumb paper...meat eating is one of the very things that made us human! Our digestive tracts shortened because we started eating meat, providing room for our brains. We diverged from gorillas/chimps for a reason......

How does it make sense that a single diet is prescribed for an entire suborder of species? Gorillas are herbivores, although frugivorous at times: completely distinct from gibbons which are strictly frugivorous: these species differ only at the family level. Even old world monkeys (cercopithecoidea, members of the same super family) have different diets: Ceboids have rumen-like stomachs and eat only grasses, have slicing molars, and cercopithecines have crushing molars and eat only fruit. Prescribing a single diet to all of these animals would be a HORRIBLE idea. Not to mention, even chimps are also distinct from humans, although we only differ at the , as their diet typically consists of much less meat.

There's no question that eating meat played an important role in our evolution but I think it overstates things to say that it is one of things that made us human, after all chimpanzees have no difficulty hunting all the meat they want yet they haven't developed larger brains over the past six million or so years. Recent findings on the evolution of human amylase gene copy number variation point to a far more plausible explanation for the shortening of our digestive tract and the development of our brains being our increased ability to digest starchy calorie dense roots and tubers as this would have provided the fuel needed for brain development.
So while I don't dispute the fact that early man did hunt much like chimpanzees and bonobos it seems probable that it was the random mutation of the AMY1 gene that proved to be the turning point in our evolution rather than an increase in meat consumption.

Explains how are meat consumption gave us room to allow our brains to grow, by allowing our digestive tracts to shrink. This is the prevailing, accepted theory among anthropologists, at least the ones I know

Also, bonobos don't eat meat really....mostly frugivorous. They are the "lovers", while chimps are the "fighters". Their point of divergence was assumed to be mate choice actually....some females preferred less violent males, and others preferred more violent males. The more violent ones=chimps, and vice versa.

Don't really understand how that study goes to prove anything along the lines of a shortened digestive tract though. It says that the divergence was maybe 200,000 years ago, when Homo sapiens evolved much earlier. Also, it says that there was directional pressure only in areas where people were fed high starch diets, and it became somewhat common by drift elsewhere, even where high-starch diets were not consumed. So, the study itself admits that many societies did not eat high-starch diets at this time...maybe I'm misinterpreting the study, but that's what I got out of it.

Explains how are meat consumption gave us room to allow our brains to grow, by allowing our digestive tracts to shrink. This is the prevailing, accepted theory among anthropologists, at least the ones I know.

I'm familiar with the expensive tissue hypothesis and it does seem to be the most likely explanation for how we developed our large brains. The question though is which foods made it all possible?

Quote:

Originally Posted by Mike Romano

Also, bonobos don't eat meat really....mostly frugivorous. They are the "lovers", while chimps are the "fighters". Their point of divergence was assumed to be mate choice actually....some females preferred less violent males, and others preferred more violent males. The more violent ones=chimps, and vice versa.

Don't really understand how that study goes to prove anything along the lines of a shortened digestive tract though. It says that the divergence was maybe 200,000 years ago, when Homo sapiens evolved much earlier. Also, it says that there was directional pressure only in areas where people were fed high starch diets, and it became somewhat common by drift elsewhere, even where high-starch diets were not consumed. So, the study itself admits that many societies did not eat high-starch diets at this time...maybe I'm misinterpreting the study, but that's what I got out of it.

Option A: Six million years ago a group of chimps became highly efficient hunters and significantly increased the amount of meat they were eating thereby increasing the quality and calorie density of their diets leading to the whole small gut big brain evolution thing.

or

Option B: Six million years ago a random gene mutation eventually lead to one group of chimps being able to better digest the starchy roots and tubers they were routinely eating thereby increasing the quality and calorie density of their diets leading to the whole small gut big brain evolution thing.